Percutaneuous temporary aortic valve

ABSTRACT

Methods and apparatuses for regulating aortic regurgitation are provided. A catheter shaft is advanced through vasculature so that a flexible occluding membrane coupled to the catheter shaft is positioned within the aorta, typically the ascending aorta above the Sinus of Valsalva and coronary ostia. Blood flow in the aorta causes the flexible occluding membrane to alternate between an expanded occluding configuration while in diastole and a collapsed lesser occluding configuration is systole. The flexible occluding membrane thereby acts as a temporary aortic valve. The flexible occluding membrane is generally conical in shape, with the tip of the cone disposed closer to the aorta than the proximal rim. In diastole, blood flow expands the flexible occluding membrane so that the proximal rim apposes the inner wall of the aorta. The flexible occluding membrane will have one or more openings to allow perfusion of the coronary arteries in diastole.

CROSS-REFERENCE

This application is a continuation of U.S. patent application Ser. No.15/083,768, filed Mar. 29, 2016, now U.S. Pat. No. 9,855,143; whichclaims the benefit of U.S. Provisional Patent Application No.62/140,111, filed Mar. 30, 2015; the full contents of which areincorporated herein by reference.

The subject matter of this application is related to the subject matterof the following co-assigned patents and pending patent applications:U.S. patent application Ser. No. 11/781,924 (filed on Jul. 23, 2007 andissued on Mar. 4, 2014 as U.S. Pat. No. 8,663,318), Ser. No. 12/180,223(filed on Jul. 25, 2008 and issued on Mar. 4, 2014 as U.S. Pat. No.8,663,319), Ser. No. 13/227,276 (filed on Sep. 7, 2011), Ser. No.14/154,890 (filed on Jan. 14, 2014), and Ser. No. 14/155,060 (filed onJan. 14, 2014), the full contents of which are incorporated herein byreference.

BACKGROUND

The present disclosure relates to medical devices, systems, and methods.In particular, the present disclosure relates to the percutaneousdelivery and deployment of a temporary aortic valve to facilitate otherpercutaneous procedures such as the delivery of aortic replacementvalves or to serve as a standalone hemodynamic support device when thenative aortic valve is damaged from infective endocarditis or trauma,for example. The native aortic valve damage may also be iatrogenic fromdeliberate valve resection prior to valve placement.

The native aortic valve can fail acutely from infection or mechanicaltrauma. In endocarditis of the aortic valve, the timing for surgery maybe limited during the active phase of the infection. The condition canbe fatal as significant acute aortic regurgitation may causedecompensating heart failure. Mechanical failure of the aortic valve canoccur from proximal aortic dissection or direct leaflet and/or annulartear with similar potential lethal outcome. Patients suffering fromsignificant aortic valve disease are frequently treated by aortic valvereplacement procedures. While most aortic valve replacements are stillperformed in open chest procedures, recently there have been significantadvances in minimally invasive aortic valve replacement where the valveis introduced through a transapical approach (minimally invasive), atransaortic approach (minimally invasive), or a transvascular(percutaneous) approach over the aortic arch. In the era oftranscatheter aortic valve intervention (TAVI), iatrogenic damage to theaortic valve may become relevant especially with suggestions for valveresection prior to replacement. The clinical needs for a percutaneoustemporary aortic valve are therefore apparent.

Transapical, transaortic, and transfemoral percutaneous aortic valveprocedures are “beating heart” procedures where continuing blood flowfrom the left ventricle into the aorta creates hemodynamic forces on thereplacement valves and the tools used in the replacement procedures. Inan effort to control the hemodynamic forces and to stabilize the toolsand valve used for replacement, that the use of a “temporary aorticvalve” (TAV) has recently been proposed. As described in commonly ownedpublished U.S. Patent Publications Nos. US 2009/0030503, US 2009/0030510and US 2012/0116439, the full disclosures of which are incorporatedherein by reference, a catheter is intravascularly introduced over theaortic arch to position a balloon assembly in the ascending aorta justabove the Sinus of Valsalva. The balloon assembly includes three equallysized balloons disposed in parallel about the distal tip of thecatheter, and the inflated balloons together limit retrograde blood flow(flow in the direction from the aorta toward the aortic valve) duringdiastole, thus limiting disturbance of the tools and/or valves locatedin the aortic valve annulus during the procedure. The balloon inflationonly partially occludes the aortic lumen in order to both allowantegrade flow during systole and to permit a limited retrograde flowduring diastole in order to perfuse the coronary vasculature through theSinus of Valsalva and to protect the left ventricle from excessivevolume overload. As a standalone procedure, in cases of naturallyoccurring damage (as opposed to iatrogenic) of the native aortic valvesuch as from infective endocarditis or trauma, the temporary aorticvalve can also be placed similarly in the ascending aorta as ahemodynamic support device.

While of great potential benefit, the use of the fixed-balloonstructures described in the prior patent applications is necessarily acompromise between resistance to regurgitation during diastole andforward blood flow patency through the aorta during systole. Even whenthe balloons are collapsed to their minimum cross-sectional area in acounter-pulsating balloon system, the complex balloon structures may becumbersome to advance through tortuous vasculature and may be prone tomechanical failure, particularly due to the relatively high number ofmechanical elements and after repeated cycles of expansion and collapse.

Previous models of catheter-based temporary aortic valves for thetreatment of acute aortic regurgitation have also not reached clinicalrelevance mostly due to their inability to adequately protect coronarycirculation. When deployed in the ascending aorta, the compromiseddiastolic coronary flow from acute aortic regurgitation has been shownto further reduce from the occlusive nature of the device designs.Myocardial ischemia can occur in acute aortic regurgitation alonewithout concomitant coronary artery disease. Coronary flow obstructionby the temporary aortic valve should therefore be overcome in improveddevice designs.

For these reasons, it would be desirable to provide improved methods andsystems for occluding the aorta to limit aortic regurgitation duringvalve repair and replacement procedures as well as to provide astandalone device for hemodynamic support in the native aortic valvewhen damaged by naturally occurring aortic regurgitation, such as frominfective endocarditis or trauma. In at least the latter application,the methods and systems can be a life-saving bridge to open heartsurgery to correct the aortic valve damage.

The following references may be of interest:

-   Aksoy S, Cam N, Guney M R, Gurkan U, Oz D, Poyraz E, Eksik A,    Agirbasli M. Myocardial ischemia in severe aortic regurgitation    despite angiographically normal coronary arteries. Tohoku J Exp Med    2012; 226(1):69-73.-   Ardehali A, Segal J, Cheitlin M. Coronary blood flow reserve in    acute aortic regurgitation. J Am Coll Cardiol 1995; 25:1387-1392.-   Davies J E, Whinnett Z I, Francis D P, Manisty C H, Aguardo-Sierra    J, Willson K, Foale R A, Malik I S, Hughes A D, Parker K H, Mayet J.    Evidence of a dominant backward-propagating “suction” wave    responsible for diastolic coronary filling in humans, attenuated in    left ventricular hypertrophy. Circulation 2006; 113 (14): 1768-78.-   Ho P C. Percutaneous aortic valve replacement: a novel design of the    delivery and deployment system. Minim Invasive Ther Allied Technol    2008; 17(3): 190-194.-   Ho P C. Percutaneous aortic valve replacement (part 2): An    innovative approach to miniaturize the delivery system based on the    novel temporary valve technology. Minim Invasive Ther Allied Technol    2009; 18(3): 172-177.-   Ho P C. Percutaneous aortic valve replacement (part 3):    Counterpulsation temporary valve technology. Minim Invasive Ther    Allied Technol 2011; 20(2):101-106.-   Ho P C. Qualitative hemodynamic validation of a percutaneous    temporary aortic valve; a proof of concept study. J Med Eng Technol    2011; 35(2):115-120.-   Ho P C, Nguyen M E, Golden P J. Percutaneous temporary aortic valve:    a proof-of-concept animal model. J Heart Valve Dis 2013; 22:460-467.-   Moulopoulos S D, Anthopoulos L, Stamatelopoulos S, Stefadouros M,    Catheter-mounted aortic valves. Ann Thorac Surg 1971; 11(5):423-430.-   Moulopoulos S D, Anthopoulos L, Antonatos P G, Adamopoulos P N,    Nanas J N. Intraaortic balloon pump for relief of aortic    regurgitation. J Thorac Cardiovasc Surg 1980; 80:38-44.-   Phillips S J, Ciborski M, Freed P S, Cascade P N, Jaron D. A    temporary catheter-tip aortic valve: hemodynamic effects on    experimental acute aortic insufficiency. Ann Thorac Surg 1976    February; 21(2):134-7.-   Quaden R, Attmann T, Boening A, Cremer J, Lutter G. Percutaneous    aortic valve replacement: Resection before impintation. Eur J    Cardiothorac Surg 2005; 27:836-840.-   Salizzoni S, Bajona P, Zehr K J, Anderson W D, Vandenberghe S,    Speziali G. Transapical off-pump removal of the native aortic valve;    a proof-of-concept animal study. J Thorac Cardiovasc Surg 2009;    138(2):468-473.-   Wendt D, Müller W, Hauck F, Thielmann M, Wendt H, Kipfmüller B,    Vogel B, Jakob H. In vitro results of a new minimally invasive    aortic valve resecting tool. Eur J Cardiothorac Surg 2009;    35(4):622-627.

SUMMARY

The issues discussed above and others may be addressed by the devices,systems, and methods of the present disclosure.

A novel percutaneous transcatheter temporary aortic valve (TAV) ispresented. The valve may include a cone-shaped membrane based occlusionelement. In ventricular systole, the occlusion element may collapse toreduce aortic obstruction. In ventricular diastole, the occlusionelement may expand to occlude the aorta to inhibit regurgitation whileallowing coronary filling through a gap or opening in the occlusionelement. The diastolic gap or opening may have a variety of sizes tobalance adequate coronary flow with protection against acuteregurgitation. In contrast with prior occlusive devices, there istypically no fixed gap size for the membrane based occlusion element insystole. By removing the systolic obstructive component of a fixed gap,the membrane based occlusion element's diastolic gap size can be smallerto provide better protection against acute regurgitation. A lower limitof the gap:aorta cross-sectional area ratio can be redefined based onadequate coronary flow. For example, based on experimental resultsand/or mathematical models, the size of the diastolic gap or opening maybe selected to optimize coronary filing while protecting against aorticregurgitation.

Aspects of the present disclosure provide temporary aortic valveapparatuses which may comprise a catheter shaft and a flexible occludingmembrane. The catheter shaft may be adapted to be advanced through avasculature of a patient for placement within an aorta or other bloodvessel of the patient. The flexible occluding membrane may have alateral side coupled to the catheter shaft and may be adapted toalternate between an expanded occluding configuration and a collapsedlesser occluding configuration in the aorta or other blood vessel insynchrony with ventricular diastole and systole.

The flexible occluding membrane may be adapted to assume the expandedoccluding configuration in response to blood flow in the aorta duringventricular diastole. The flexible occluding membrane may be adapted toassume the collapsed lesser occluding configuration in the aorta inresponse to blood flow therein during ventricular systole.

The flexible occluding membrane may have an opening to allow bloodperfusion therethrough when in the expanded occluding configuration. Theopening may be positioned at substantially a center of the flexibleoccluding membrane. The opening and the center of the flexible occludingmembrane may be disposed at a distal tip of the flexible occludingmembrane. Alternatively or in combination, the opening may be positionedat a location offset from a center of the flexible occluding membrane.The flexible occluding membrane may have a plurality of openings toallow blood perfusion therethrough when in the expanded occludingconfiguration. The opening(s) may have a variety of cross sectionalsizes. For example, the opening(s) may have a cross-sectional size of50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% orless, 20% or less, 15% or less, 10% or less, or 5% or less, to name offew sizes, of the aorta or other blood vessel.

The catheter shaft may further comprise a distal anchoring loop. Thedistal anchoring loop may have an expanded, curved configuration and acollapsed, straightened configuration. In the expanded, curvedconfiguration, the distal anchoring loop may anchor the catheter shaftand the flexible occluding membrane in the aorta or other blood vessel.For example, the distal anchoring loop may be sized to appose and/orexert a radially outward force on the inner wall of the aorta or otherblood vessel when in the expanded, curved configuration, therebyanchoring the catheter shaft and the flexible occluding membrane inplace. In the collapsed, straightened configuration, the distalanchoring loop may be in a smaller cross-section configuration tofacilitate the advancement and removal of the catheter shaft and theflexible occluding membrane.

The flexible occluding membrane may have a conical shape. Theconically-shaped flexible occluding membrane may comprise an annularproximal lip adapted to appose an inner wall of the aorta when theflexible occluding membrane is in the expanded occluding configuration.The conical shape of the flexible occluding membrane may be orientedwith the larger opening (proximal lip) away from the aortic valve. Theflexible occluding membrane may be adapted to be positioned within anascending aorta of the patient to provide occlusion therein. Theflexible occluding membrane may be adapted to be positioned within theascending aorta just above the Sinus of Valsalva and coronary ostia. Forexample, the diameter of the annular proximal lip may be selected toclosely match or exceed that of a typical human ascending aorta abovethe Sinus of Valsalva and coronary ostia.

Aspects of the present disclosure also provide temporary aortic valveapparatuses comprising a catheter shaft and a flexible occludingmembrane having an opening to allow blood perfusion therethrough whenthe membrane is in an expanded configuration. The catheter shaft may beadapted to be advanced through a vasculature of a patient for placementwithin an aorta or other blood vessel of the patient. The flexibleoccluding membrane may be coupled to the catheter shaft and adapted toalternate between an expanded occluding configuration and a collapsedlesser occluding configuration in the aorta in synchrony withventricular diastole and systole.

The catheter shaft and the flexible occluding membrane may be coupled toone another at a center of the flexible occluding membrane or at alocation offset from a center of the flexible occluding membrane.

The flexible occluding membrane may be adapted to assume the expandedoccluding configuration in response to blood flow in the aorta duringventricular diastole. The flexible occluding membrane may be adapted toassume the collapsed lesser occluding configuration in the aorta inresponse to blood flow therein during ventricular systole.

The opening may be positioned at substantially a center of the flexibleoccluding membrane. The opening and the center of the flexible occludingmembrane may be disposed at a distal tip of the flexible occludingmembrane. The opening may be positioned at a location offset from acenter of the flexible occluding membrane. The flexible occludingmembrane may have a plurality of openings to allow blood perfusiontherethrough when in the expanded occluding configuration. Theopening(s) may have a variety of cross sectional sizes. For example, theopening(s) may have a cross-sectional size of 50% or less, 45% or less,40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% orless, 10% or less, or 5% or less, to name of few sizes, of the aorta orother blood vessel.

The catheter shaft may comprise a distal anchoring loop. The distalanchoring loop may have an expanded, curved configuration and acollapsed, straightened configuration. In the expanded, curvedconfiguration, the distal anchoring loop may anchor the catheter shaftand the flexible occluding membrane in the aorta or other blood vessel.For example, the distal anchoring loop may be sized to appose and/orexert a radially outward force on the inner wall of the aorta or otherblood vessel when in the expanded, curved configuration, therebyanchoring the catheter shaft and the flexible occluding membrane inplace. In the collapsed, straightened configuration, the distalanchoring loop may be in a smaller cross-section configuration tofacilitate the advancement of the catheter shaft and the flexibleoccluding membrane.

The flexible occluding membrane may have a conical shape. Theconically-shaped flexible occluding membrane may comprise an annularproximal lip adapted to appose an inner wall of the aorta when theflexible occluding membrane is in the expanded occluding configuration.The flexible occluding membrane may be adapted to be positioned withinan ascending aorta of the patient to provide occlusion therein. Theflexible occluding membrane may be adapted to be positioned within theascending aorta just above the Sinus of Valsalva and coronary ostia. Forexample, the diameter of the annular proximal lip may be selected toclosely match or exceed that of a typical human ascending aorta justabove the Sinus of Valsalva and coronary ostia.

Aspects of the present disclosure may also provide methods forregulating aortic regurgitation during an aortic valve diagnostic ortreatment procedure. A catheter shaft may be advanced through avasculature of a patient so that a flexible occluding membrane having alateral side coupled to the catheter shaft is positioned within an aortaor other blood vessel of the patient. Blood flow in the aorta may causethe flexible occluding membrane to alternate between an expandedoccluding configuration and a collapsed lesser occluding configurationin synchrony with ventricular diastole and systole. Blood flow in theaorta during ventricular diastole may cause the flexible occludingmembrane to assume the expanded occluding position. The flexibleoccluding membrane may passively alternate between the configurationsdue to the blood flow, thereby obviating the need for any active,mechanical actuation of device and reducing risks of mechanical failureof the device. Expansion of the flexible occluding member duringventricular diastole may inhibit aortic regurgitation.

In advancing the catheter shaft, the flexible occluding membrane may bepositioned within the ascending aorta above the Sinus of Valsalva andcoronary ostia. Expansion of the flexible occluding member duringventricular diastole may inhibit aortic regurgitation while allowingperfusion of the coronary arteries via the Sinus of Valsalva. Perfusionof the coronary arteries via the Sinus of Valsalva may be allowed by anopening on the flexible occluding membrane. The opening may bepositioned at a variety of locations. There may be more than oneopening. The opening may be positioned at substantially a center of theflexible occluding membrane. The opening and the center of the flexibleoccluding membrane may be disposed at a distal tip of the flexibleoccluding membrane. The opening may be positioned at a location offsetfrom a center of the flexible occluding membrane. Perfusion of thecoronary arteries via the Sinus of Valsalva may be allowed by aplurality of openings on the flexible occluding membrane. The opening(s)may have a variety of cross sectional sizes. For example, the opening(s)may have a cross-sectional size of 50% or less, 45% or less, 40% orless, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less,10% or less, or 5% or less, to name of few, of the aorta or other bloodvessel.

A distal anchoring loop of the catheter shaft may be expanded to acurved configuration to anchor the catheter shaft and the flexibleoccluding membrane in the aorta or other blood vessel. For example, thedistal anchoring loop may be expanded to a size in which it apposesand/or exerts a radially outward force on the inner wall of the aorta orother blood vessel, thereby anchoring the catheter shaft and theflexible occluding membrane in place. The distal anchoring loop may havean expanded, curved configuration and a collapsed, straightenedconfiguration. To advance or retract the distal anchoring loop, it maybe collapsed and/or straightened to a lower cross-sectional areaconfiguration.

The flexible occluding membrane may have a conical shape and an annularproximal lip. Blood flow in the aorta during diastole may cause theannular proximal lip to appose an inner wall of the aorta. Blood flow inthe aorta during ventricular systole may cause the flexible occludingmembrane to assume the collapsed lesser occluding configuration.Collapse of the flexible occluding membrane during ventricular systolemay lessen inhibition of blood flow from a left ventricle of the patientto the aorta.

An aortic valve replacement or repair procedure may be performed whileblood flow in the aorta continues to cause the flexible occludingmembrane to alternate between the expanded occluding configuration andthe collapsed lesser occluding configuration in synchrony with diastoleand systole. An example of such a procedure may include the advancementof a replacement valve through a lumen of the catheter shaft.

The catheter shaft may be advanced over an aortic arch of the patient.The catheter shaft may be advanced or introduced to the aorta or otherblood vessel transapically, transaortically, or transfemorally, to namea few approaches.

Aspects of the present disclosure may also provide methods forregulating aortic regurgitation during an aortic valve diagnostic ortreatment procedure. A catheter shaft may be advanced through avasculature of a patient so that a flexible occluding membrane coupledto the catheter shaft is positioned within an aorta or other bloodvessel of the patient. Blood flow in the aorta may cause the flexibleoccluding membrane to alternate between an expanded occludingconfiguration and a collapsed lesser occluding configuration insynchrony with ventricular diastole and systole. Perfusion of thecoronary arteries via the Sinus of Valsalva may be allowed by an openingon the flexible occluding membrane. Blood flow in the aorta or otherblood vessel during ventricular diastole may cause the flexibleoccluding membrane to assume the expanded occluding position. Theflexible occluding membrane may passively alternate between theconfigurations due to the blood flow, thereby obviating the need for anyactive, mechanical actuation of device and reducing risks of mechanicalfailure of the device. Expansion of the flexible occluding member duringventricular diastole may inhibit aortic regurgitation.

The opening may be positioned at a variety of locations. There may bemore than one opening. The opening may be positioned at substantially acenter of the flexible occluding membrane. The opening and the center ofthe flexible occluding membrane may be disposed at a distal tip of theflexible occluding membrane. The opening may be positioned at a locationoffset from a center of the flexible occluding membrane. Perfusion ofthe coronary arteries via the Sinus of Valsalva may be allowed by aplurality of openings on the flexible occluding membrane. The opening(s)may have a variety of cross sectional sizes. For example, the opening(s)may have a cross-sectional size of 50% or less, 45% or less, 40% orless, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less,10% or less, or 5% or less, to name of few, of the aorta or other bloodvessel.

A distal anchoring loop of the catheter shaft may be expanded to acurved configuration to anchor the catheter shaft and the flexibleoccluding membrane in the aorta or other blood vessel. For example, thedistal anchoring loop may be expanded to a size in which it apposesand/or exerts a radially outward force on the inner wall of the aorta orother blood vessel, thereby anchoring the catheter shaft and theflexible occluding membrane in place. The distal anchoring loop may havean expanded, curved configuration and a collapsed, straightenedconfiguration. To advance or retract the distal anchoring loop, it maybe collapsed and/or straightened to a lower cross-sectional areaconfiguration.

In advancing the catheter shaft, the flexible occluding membrane may bepositioned within the ascending aorta above the Sinus of Valsalva andcoronary ostia. Expansion of the flexible occluding member duringventricular diastole may inhibit aortic regurgitation while allowingperfusion of the coronary arteries via the Sinus of Valsalva.

The flexible occluding membrane may have a conical shape and an annularproximal lip. Blood flow in the aorta during diastole may cause theannular proximal lip to appose an inner wall of the aorta. Blood flow inthe aorta during ventricular systole may cause the flexible occludingmembrane to assume the collapsed lesser occluding configuration.Collapse of the flexible occluding membrane during ventricular systolemay lessen inhibition of blood flow from a left ventricle of the patientto the aorta.

An aortic valve replacement or repair procedure may be performed whileblood flow in the aorta continues to cause the flexible occludingmembrane to alternate between the expanded occluding configuration andthe collapsed lesser occluding configuration in synchrony with diastoleand systole. An example of such a procedure may include the advancementof a replacement valve through a lumen of the catheter shaft.

The catheter shaft may be advanced over an aortic arch of the patient.The catheter shaft may be advanced or introduced to the aorta or otherblood vessel transapically, transaortically, or transfemorally, to namea few approaches.

The flexible occluding membrane may be coupled to the catheter shaft ata center of the flexible occluding membrane. The flexible occludingmembrane may be coupled to the catheter shaft at a location of theflexible occluding membrane offset from a center of the flexibleoccluding membrane.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the present disclosure are set forth withparticularity in the appended claims. It should be noted that thedrawings are not to scale and are intended only as an aid in conjunctionwith the explanations in the following detailed description. In thedrawings, identical reference numbers identify similar elements or acts.The sizes and relative positions of elements in the drawings are notnecessarily drawn to scale. For example, the shapes of various elementsand angles are not drawn to scale, and some of these elements arearbitrarily enlarged and positioned to improve drawing legibility.Further, the particular shapes of the elements as drawn, are notintended to convey any information regarding the actual shape of theparticular elements, and have been solely selected for ease ofrecognition in the drawings. A better understanding of the features andadvantages of the present disclosure will be obtained by reference tothe following detailed description that sets forth illustrativeembodiments, in which the principles of the present disclosure areutilized, and the accompanying drawings of which:

FIG. 1A shows a side view of a temporary aortic valve apparatus,according to some embodiments;

FIG. 1B shows a perspective view of the front of the temporary aorticvalve apparatus of FIG. 1A;

FIG. 1C shows a perspective view of the back and proximal lip of thetemporary aortic valve apparatus of FIG. 1A;

FIG. 1D shows a front view of the temporary aortic valve apparatus ofFIG. 1A;

FIG. 1E shows a perspective view of a distal end and the anchoring loopof the catheter shaft of the temporary aortic valve apparatus of FIG.1A;

FIG. 1F shows a magnified view of the distal end and the anchoring loopof the catheter shaft of the valve apparatus of FIG. 1A placed invessel;

FIG. 1G shows a side view of another temporary aortic valve apparatus,according to some embodiments;

FIG. 1H shows a front view of the temporary aortic valve apparatus ofFIG. 1G;

FIG. 2A shows the temporary aortic valve apparatus of FIG. 1A positionedin the ascending aorta of a subject to be in its expanded configurationwhile the heart is in diastole, according to some embodiments;

FIG. 2B shows the temporary aortic valve apparatus of FIG. 1A positionedin the ascending aorta of the subject to be in its collapsedconfiguration while the heart is in systole, according to someembodiments;

FIG. 3A shows a transapical temporary aortic valve apparatus positionedin the ascending aorta of the subject to be in its expandedconfiguration while the heart is in diastole, according to someembodiments;

FIG. 3B shows a transapical temporary aortic valve apparatus positionedin the ascending aorta of the subject to be in its collapsedconfiguration while the heart is in systole, according to someembodiments;

FIG. 4 shows a schematic of a testing apparatus used to test temporaryaortic valve apparatuses, according to some embodiments;

FIG. 5A shows the temporary aortic valve apparatus of FIG. 1A in itsexpanded configuration in the testing apparatus of FIG. 4 whensimulating diastole;

FIG. 5B shows the temporary aortic valve apparatus of FIG. 1A in itscollapsed configuration in the testing apparatus of FIG. 4 whensimulating systole; and

FIG. 6 shows a table of fluid volume distributions of temporary aorticvalve apparatuses tested in the testing apparatus of FIG. 4.

DETAILED DESCRIPTION

FIG. 1A shows a side view of a temporary aortic valve apparatus 100.FIG. 1B shows a perspective view of the front of the temporary aorticvalve apparatus 100. FIG. 1C shows a perspective view of the back of thetemporary aortic valve apparatus 100. FIG. 1D shows a front view of thetemporary aortic valve apparatus 100. FIG. 1E shows a distal portion 110a of the temporary aortic valve apparatus 100. FIG. 1F shows the distalportion 110 a of the temporary aortic valve apparatus 100 placed in avessel. FIG. 1G shows a side view of an embodiment of the temporaryaortic valve apparatus 100. FIG. 1H shows a front view of an embodimentof the temporary aortic valve apparatus 100.

The temporary aortic valve apparatus 100 may comprise a catheter shaft110 and a flexible occluding membrane 120 attached to the catheter shaft110. The flexible occluding membrane 120 may be attached to the cathetershaft 110 near the distal portion 110 a of the catheter shaft 110. Theflexible occluding membrane 120 may have an axially distal end 120 a andan axially proximal end 120 b. A lateral side 126 of the flexibleoccluding membrane 120 is attached to the catheter shaft 110 such thatthe flexible occluding membrane 120 is axially aligned with the cathetershaft 110, with both the distal end 120 a and the proximal end 120 bbeing attached to the flexible occluding membrane. As shown in FIGS. 1Eand 1F, the distal portion 110 a of the catheter shaft 110 may include alarge distal loop 112 at the distal end to aid in anchoring thetemporary aortic valve apparatus 100. The large distal loop 112 mayinclude one or more radiopaque markers 114 to allow it to be visualizedduring a surgical procedure. FIG. 1F shows the large distal loop 112anchoring the temporary aortic valve apparatus 100 in a vessel such as ablood vessel. The large distal loop 112 can appose the inner wall of thevessel and the friction therebetween can anchor the large distal loop112 and the TAV 100 in place. In some embodiments, the large distal loop112 is actuated between expanded and collapsed configurations so thatthat catheter shaft 110 can be engaged and disengaged from the vesselwall. In the collapsed configuration, the large distal loop 112 may bestraightened by an advancable, internal guidewire or other mechanism.The collapsed (e.g., straightened) configuration of the loop 112 mayfacilitate the delivery of the TAV to the ascending aorta and/or itsremoval from the vasculature. The distal end portion 110 a of thecatheter shaft 110 may be pre-formed to have the large distal loop 112.When the straightening guide wire is removed, the large distal loop 112may resiliently return to its curved shape. Alternatively, the largedistal loop 112 can be pre-formed to be straight and can be curved orlooped with the advancement of a guidewire with a curved endtherethrough.

The flexible occluding membrane 120 may be expandable and collapsible.Generally, when placed in a bodily vessel such as a blood vessel, thedirection of fluid flow may dictate whether the flexible occludingmembrane 120 is in its expanded or collapsed configuration. The flexibleoccluding membrane 120 may be conical in shape, with the conical shapetapering toward the distal end 120 a. The flexible occluding membrane120 may have a large proximal opening or gap 124 such that fluid (e.g.,blood) flow in the direction of the taper causes fluid to flow into theproximal opening 124 to cause the flexible occluding membrane 120 toexpand. When expanded, the circumferential or annular lip on theproximal end 120 b of the flexible occluding membrane 120 may appose theinner wall of the bodily vessel. Generally, the circumferential orannular lip on the proximal end 120 b is sized such that when expanded,it fully apposes the annular inner wall of the bodily vessel such as theascending aorta (i.e., the diameter of the distal end 120 b whenexpanded may be greater or equal to the diameter of the inner wall ofthe target bodily vessel). The distal end 120 a of the flexibleoccluding membrane 120 may have a smaller opening or gap 122 whichallows some fluid to pass through the expanded flexible occludingmembrane 120. The opening or gap 122 may be a cut-out section of the tipof the conical membrane 120. In some cases, the flexible occludingmembrane 120 may be biased to be in the expanded configuration evenwithout fluid flow in the direction of the taper. When fluid (e.g.,blood) flows in the opposite direction, fluid flowing past the outersurface of the flexible occluding membrane 120 may urge the flexibleoccluding membrane 120 to collapse.

As shown in FIGS. 1A to 1D, the temporary aortic valve apparatus 100 mayhave the distal opening or gap 122 positioned closely relative to thecatheter shaft 110. Other locations of the distal opening or gap 122 arealso contemplated. As shown in FIGS. 1G and 1H, the opening or gap 122may be spaced apart from the catheter shaft 110 while still beingpositioned at the distal tip 120 a of the flexible occluding membrane120. A proximal, lateral portion 126 b of the flexible occludingmembrane 120 is attached to the catheter shaft 110 while a distallateral portion 126 a of the flexible occluding membrane remains free.Further locations of the distal opening or gap 122 are alsocontemplated. For example, the distal opening or gap 122 may be slightlyoffset from the distal tip 120 a of the flexible occluding membrane 120.While one distal opening or gap 122 is shown, having a plurality ofdistal openings or gaps is also contemplated. For example, there may bea plurality of distal openings or gaps 122 distributed about the distaltip 120 a of the flexible occluding membrane in some embodiments.

As shown in FIGS. 1E and 1F, the distal portion 110 a of the cathetershaft 110 may include a large distal loop 112 at the distal end to aidin anchoring the temporary aortic valve apparatus 100. The large distalloop 112 may include one or more radiopaque markers 114 to allow it tobe visualized during a surgical procedure.

FIGS. 2A and 2B show the temporary aortic valve apparatus 100 positionedin the aorta AOR of a subject. In particular, the temporary aortic valveapparatus 100 is positioned in the ascending aorta AA superior to theaortic valve AV. To position the temporary aortic valve apparatus 100 inthis location, the temporary aortic valve apparatus may have beenintroduced percutaneous with a delivery catheter and navigatedsuperiorly in the descending aorta DA and across the arch of the aortaAOA to reach the ascending arota AA. The temporary aortic valveapparatus 100 may be positioned so that the distal opening 122 issuperior of the aortic valve AV, the right coronary artery RCA, and theleft coronary artery LCA and so that the proximal opening 124 isinferior of the aortic arch AOA and superior of the Sinus of Valsalva.The proximal opening 124 may be positioned to be inferior of the arch ofthe aorta AOA, the brachiocephalic artery BA (which leads to the rightsubclavian artery RCA and the right common carotid artery RCCA), theleft common carotid artery LCCA, and the left subclavian artery LSA. Thelarge distal loop 112 can be expanded to appose the inner wall of theascending aorta superior to the Sinus of Valsalva and the coronary ostiato anchor the temporary aortic valve apparatus 100 in place.

In FIG. 2A, the heart is in diastole and the leaflets of the aorticvalve AV have closed. In the presence of atrioventricular damage, therewould be aortic regurgitation at the aortic valve AV in diastole. Thetemporary aortic valve apparatus 100 may therefore assume the expandedconfiguration, with the flexible occluding membrane 120 expanded and theouter circumferential lip of the distal end 120 b of the flexibleoccluding membrane 120 opposing the inner wall of the ascending aortaAA. The flexible occluding membrane 120 may be biased to be in theexpanded configuration. Blood flow back toward the aortic valve AV asshown by arrows 200 may pass through the expanded flexible occludingmembrane 120 to pass through the openings 124 and 122 to perfuse theright coronary artery RCA and the left coronary artery LCA.

In FIG. 2B, the heart is in systole and the leaflets of the aortic valveAV have opened. Blood flow through the aortic valve AV and aorta AO asindicated by arrows 201 may cause the flexible occluding membrane 120 tocollapse and the temporary aortic valve apparatus 100 to thereforeassume the collapsed configuration. The large distal loop 112 cancontinue to anchor and maintain the position the temporary aortic valveapparatus 100 throughout the cardiac cycle in both systole and diastole.

As described above, the temporary aortic valve apparatus 100 willtypically be configured to be delivered percutaneous. For example, thetemporary aortic valve apparatus 100 may have been deliveredtransfemorally as shown in FIGS. 2A and 2B. Temporary aortic valveapparatuses of the present disclosure may be configured for otherapproaches as well. For example, a transaortic approach may be usedinstead of a transfemoral approach to introduce the temporary aorticvalve apparatus 100 to the target location shown in FIGS. 2A and 2B. Inother examples, a transapical approach as described below and herein maybe used. The temporary aortic valve apparatus 100 will typically beintroduced to the target treatment site through the inner lumen of adelivery catheter. The delivery catheter may constrain the flexibleoccluding membrane 120 to be in its collapsed configuration so that thedelivery catheter and the temporary aortic valve apparatus 100 may benavigated through the vasculature in a minimal cross-sectionconfiguration or otherwise introduced in a minimal cross-sectionconfiguration.

FIG. 3A shows a transapical temporary aortic valve apparatus 300advanced through the left ventricle of the heart HRT to be positioned inthe ascending aorta AA. The transapical temporary aortic valve apparatus300 may have device components similar to those of the percutaneoustemporary aortic valve apparatus 100. The transapical temporary aorticvalve apparatus 300 may comprise a catheter shaft 310 coupled to aflexible occluding membrane 320. The flexible occluding membrane 320 maybe conical in shape and have a taper in the proximal direction, that is,the distal opening or gap 324 at the distal tip is larger than theproximal opening at the proximal tip of the flexible occluding membrane320. The distal end of the temporary aortic valve apparatus 300 may havea distal loop, similar to the loop 112 of the temporary aortic valveapparatus 100 described above and herein, to facilitate anchoring withinthe aorta.

In FIG. 3A, the heart is in diastole and the leaflets of the aorticvalve AV have closed. The temporary aortic valve apparatus 300 maytherefore assume the expanded configuration, with the outercircumferential lip of the distal end of the flexible occluding membrane120 opposing the inner wall of the ascending aorta AA. Blood flow backtoward the aortic valve AV as shown by arrows 300 may pass through theexpanded flexible occluding membrane 320 to pass through the openings324 and 322 to perfuse the right coronary artery RCA and the leftcoronary artery LCA.

In FIG. 3B, the heart is in systole and the leaflets of the aortic valveAV have opened. Blood flow through the aortic valve AV and aorta AO asindicated by arrows 301 may cause the flexible occluding membrane 320 tocollapse and the temporary aortic valve apparatus 300 to thereforeassume the collapsed configuration.

EXPERIMENTAL

The inventor has tested a prototype cone-shaped membrane occlusionapparatus substantially the same as the apparatus 100 as describedabove. Occlusion devices with different gap cross-sectional area toaortic cross-sectional area ratios were tested. Three prototypes withreducing gap:aorta cross-sectional area ratios—35%, 15%, and 0%—weretested in a flow chamber of simulated acute severe aortic regurgitation.Correspondingly, increasing in forward cardiac output volumes, coronaryflow:aortic regurgitant volume ratios and reduction in aorticregurgitant volumes were observed (p<0.001). Based on suchexperimentation, an optimal gap:aorta cross-sectional ratio for thecone-shaped membrane occlusion device can be determined. A clinicallyuseful percutaneous device for the management of acute severe aorticregurgitation (e.g., to provide hemodynamic support) may be developedbased on this determined optimal ratio.

FIG. 4 shows a schematic of a testing apparatus 400 used to test thetemporary aortic valve apparatuses. The apparatus comprises an inputreservoir tank 410 storing fluid which flows through the channel 415 toprovide fluid flow to a main channel 420 where the temporary aorticvalve testing site 425 is located. The fluid may also flow through themain channel 420 to an output reservoir tank 430 and a cardiac outputvolume measurement apparatus 435. On the opposite side, the fluid mayalso flow through the main channel 420 through channel 450 which leadsto an aortic regurgitant volume measurement apparatus 455. The fluid mayalso flow through the main channel 420 through a channel 460 leading toa coronary flow volume measurement apparatus 465. The channels 415, 420,and 450 may comprise clear polyvinyl chloride (PVC) tubing with a 2.54cm internal diameter and the channel 460 may also comprise a clearpolyvinyl chloride (PVC) tubing but with a 0.635 cm internal diameter.The PVC tubings used may be obtained from Kuriyama of America, Inc. ofSchaumburg, Ill.

The testing apparatus 400 may further comprise valves (e.g.,electrically actuated ball valves 24 VAC available from DynaquipControls Corp. of St. Clair, Mich.) 440 and 445. The valve 440 mayseparate the channel 415 and the main channel 420. The valve 445 mayseparate the main channel 420 with the channel 450. When the valve 445is open, fluid may be allowed to flow through the channel 450 to reachthe aortic regurgitant volume measurement apparatus 455. When the valve445 is open, more fluid is allowed to flow through the channel 460 toreach the coronary flow volume measurement apparatus 460.

The valves 440, 445 may be open and closed to provide pulsatile fluidflow through the main channel 420, simulating the pulsatile blood flowin the aorta. Pulsatile flow conditions of the ascending aorta with orwithout induced aortic regurgitation (AR) may be simulated. Theautomatic and adjustable timing cycles of the two valves 440, 445 may becreated via an electrical circuit with a repeat cycle time delay relay(e.g., available from Dayton Electric Co. of Niles, Ill.) and twocontrol transformers 120/24 VAC (e.g., available from Veris Industriesof Portland, Oreg.). The two valves 440, 445 may be coordinated suchthat normal flow conditions with an intact aortic valve and acutewide-open aortic regurgitation can be simulated at the testing site 425.

The tested temporary aortic valve (TAV) apparatus 100 comprised acone-shaped latex membrane 120 having a thickness of 0.33 mm. Themembrane 120 was affixed to a standard 5-Fr. standard catheter 110. Thedimensions of the latex cone were as follows: the diameter of thecone-opening (circular lip) at the proximal end 120 b was slightlylarger than the diameter of the inner tubing wall (2.54 cm) at the testsite 425 representing the ascending aorta. The slightly larger size waschosen to ensure sufficient apposition of the conical membrane 120 tothe aorta during diastole when the conical membrane 120 is open. Thedepth of the conical membrane, from proximal lip to distal tip, wasarbitrarily set at 5 cm. The gap or opening 122 was created by cuttingthe tip of the conical membrane 120 such that the cross-sectional areaof the gap-opening 122 with respect to the aorta can be specified.

While certain dimensions, parameters, and component materials of thetested temporary aortic valve (TAV) apparatus 100 are disclosed above,it is to be understood that such dimensions, parameters, and componentmaterials are provided as examples only. It will be understood that inpractice, the temporary aortic valve apparatus 100 may encompass avariety of dimensions, parameters, and component materials withoutdeparting from the scope of the present disclosure.

FIG. 5A shows the temporary aortic valve apparatus 100 in its expandedconfiguration in the testing site 425 of the testing apparatus 400 whensimulating diastole. Retrograde fluid flow in the direction indicated byarrow 500 can enter the proximal opening 124 to expand the flexibleoccluding membrane 120. Alternatively or in combination, the conicalmembrane 120 may also assume its original expanded configuration in theabsence of forward fluid flow. The conical membrane 120 in the expandedconfiguration may provide retrograde resistance to aortic regurgitationwhile the pre-fabricated gap 122 may control residual aorticregurgitation and allow for coronary filling.

FIG. 5B shows the temporary aortic valve apparatus 100 in its collapsedconfiguration in the testing site 425 of the testing apparatus 400 whensimulating systole. Forward fluid flow in the direction indicated byarrow 501 collapses the flexible occluding membrane 120.

Flow volumes were collected at respective sites representing the forwardcardiac output, aortic regurgitant flow, and coronary flow over a1-minute run comprising 12 cycles. Volumes were measured under theconditions of baseline normal (with intact aortic valve; ball-valve (B)closed throughout cycles), simulated acute severe aortic regurgitation(AR) (alternating opening and closing of ball-valves (A) and (B) percycle) and acute severe AR with TAV protection. The TAV prototypestested had 35%, 15%, and 0% gap:aorta cross-sectional area ratios at thecone-tip, respectively. Data for each condition was averaged over 3runs. All volume measurements were collected in liters (1). Statisticalanalyses of the volume differences during the various conditions wereperformed using ANOVA.

Results. The three prototypes with reducing gap:aorta cross-sectionalarea ratios (35%, 15%, 0%) were tested in the flow chamber of simulatedacute severe aortic regurgitation (e.g., the testing apparatus 400).Correspondingly, increasing in forward cardiac output volumes, coronaryflow:aortic regurgitant volume ratios and reduction in aorticregurgitant volumes were observed (p<0.001). The large distal catheterloop of the prototype devices were successful in immobilizing theconical membrane from any undue axial movements along the length of thetubing or mock “aorta.”

FIG. 6 shows a table of the experimental results. Compared to the normalbaseline normal condition, simulated acute severe AR showed a drop inthe forward cardiac output volume (from 21.12+/−0.49 to 14.43+/−0.18),decrease in the coronary flow volume (from 1.97+/−0.06 to 1.78+/−0.01)and a sharp presence of aortic regurgitant volume (From 0 to8.07+/−0.08).

With membrane TAV protection during simulated acute severe AR, there wasa significant increase in the forward cardiac output volumes as the TAVgap size decreased from 35% to 0% (p<0.001). Along with the smaller TAVgap sizes, the aortic regurgitant volume significantly decreased whilethe coronary flow:aortic regurgitant ratio significantly increased (bothwith p<0.001). The absolute coronary flow volume did not drop with TAVdeployment of any gap size.

It will be understood that the results were conducted with the prototypeTAV apparatus 100 and that variations to the experimental results mayoccur with different testing parameters and/or modifications to the TAVapparatus 100. The experimental results are provided as examples.

Discussion. Prior 3-balloon TAV devices were also studied. These3-balloon TAV devices may be challenged due to the fixed nature of thegap provided. (Ho P C, Minim Invasiv Ther Allied Technol 2008; Ho P C, JMed Eng Technol 2011; Ho P C, J Heart Valve Dis 2013.) During systole,the fixed TAV gaps from the inflated balloons may represent forwardaortic flow resistance and may affectively create an artificialstenosis. Although calculated at moderate range, the effective TAVaortic stenosis could limit its application in patients with acompromised left ventricle. Subsequent addition of ballooncounter-pulsation to the balloon-based TAV device, however, couldpotentially lessen forward aortic flow resistance. (Ho P C, MinimInvasive Ther Allied Technol 2011.)

The TAV devices of the present disclosure may include conical membranesthat may be collapsible during systole and fully expandable in diastolebased on the passive forces of the aortic flow, with a gap-to-aortacross-sectional area ratio that can be tailored to optimize aorticregurgitation protection and coronary flow. The conical membrane of thetested TAV device may have a shape may cause the lip of the conicalmembrane to be in apposition with the aortic (tubing) wall, such thatthe diastolic regurgitant flow (for coronary filling) could becontrolled at the pre-specified gap at the cone-tip. The elegance of theconical membrane temporary aortic valve was demonstrated by thecollapsibility of the conical membrane due to the passive forces of theaortic flow. As the lip of the conical membrane becomes in appositionwith the tubing or mock “aortic” wall during diastole, diastolicregurgitant flow (e.g., for coronary filling) could be controlled at thepre-specified opening or cap at the membrane tip. Without the concernfor systolic flow obstruction in the test system versus in vivo, a lowerlimit of the gap:aorta cross-sectional area could be determined. Becausethe mathematical model for the 3-balloon TAV model calculated the gap tobe at 35% of the aortic crosss-sectional area, the selection for themembrane TAV gap sizes in this study began at 35%, followed by 15%, and0%. While these specific gap size percentages were tested, other TAV gapsizes such as 50%, 40%, 30%, 20%, or 10% are also contemplated.

The 0% TAV gap was chosen as a control for the study construct includingthe flow apparatus and the membrane TAV prototype. Ideally, no AR wouldbe expected at 0% TAV gap. In the experiment using the TAV with 0% gap,however, the aortic regurgitant volume was quite high even though it wasmuch less than using TAV with larger gaps (table 1, FIG. 6). Theexcessive AR findings may be explained by the TAV prototype assembly 100and the experimental setup 400. The imperfect seal of the TAV prototype100 may be caused by inadequate apposition of the cone-lip to the tubingwall and/or device-related mal-apposition against the tubing wall. Inthis regard, the TAV devices of the present disclosure may bemanufactured to provide improvements over the tested, pre-clinical TAVprototype device based on factors such as membrane material selection,catheter stiffness and french-size selection, and mounting technique ofthe membrane to the catheter 110.

With decreasing TAV gap sizes, the gradual improvements in the forwardcardiac output volumes and reduction in the aortic regurgitant volumesare encouraging results. The lack of coronary flow volume response canbe viewed as a positive finding in conjunction with the improvements inthe coronary:regurgitant volume ratios. Unintentional allowance ofsignificant AR by the membrane TAV prototype may explain this lack ofcoronary flow improvement, which may improve with further manufacturingas mentioned. In a published study of a temporary valve with no built-ingaps, however, device deployment caused further decline in coronary flowrates already compromised by induced acute aortic regurgitation(Salizzoni S, J Thorac Cardiovasc Surg 2009). Our membrane TAV prototype100 did not reduce the coronary flow during deployment while sustaininga significant reduction in aortic regurgitation.

Refinement of the gapped device may be contingent upon redefining thelow-limit for the size of the gap 122 in the membrane TAV device 100,such that it can provide the maximal AR protection without restrictingcoronary flow. With this approach of device optimization, the coronaryflow could rise at improved TAV AR protection. The high speed of theaortic regurgitant jet has been attributed to coronary flow reduction atsevere range acute AR. Reversal of diastolic coronary flow due toVenturi effect from the high speed regurgitant jet has been suggested(Ardehali A, J Am Coll Cardiol 1995). Our in vitro flow apparatus 400also may not be able to reproduce the physiologic “suction” wave ofcoronary microvasculature in diastolic filling (Davies J E, Circulation2006). By reducing the speed of the aortic regurgitant flow with themembrane TAV, diastolic coronary filling could be optimized by lesseninglikelihood for coronary flow reversal in significant AR. The regurgitantblood volume may be more likely to enter the coronary bed with its loweroutflow pressure in the right atrium and its “suction” effect ofdiastolic filling versus the left ventricle.

The study performed may also be limited by the typical inability of invitro flow models such as the flow model 400 to completely simulatephysiologic conditions. Also, the TAV prototype 100 used was anapproximation of the pre-clinical vision with contemplated improvementsin material selection and manufacturing processes as discussed. As such,the study provides qualitative proof of concept evaluation of apromising membrane transcatheter TAV device 100. The findings suggest alower limit for the gap:aorta dimensional ratio could be determined tooptimize aortic regurgitation protection while allowing for optimaldiastolic coronary filling.

While preferred embodiments of the present disclosure have been shownand described herein, it will be obvious to those skilled in the artthat such embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the present disclosure. It should beunderstood that various alternatives to the embodiments of the presentdisclosure described herein may be employed in practicing the presentdisclosure. It is intended that the following claims define the scope ofthe invention and that methods and structures within the scope of theseclaims and their equivalents be covered thereby.

What is claimed is:
 1. A temporary aortic valve apparatus comprising: acatheter shaft adapted to be advanced through a vasculature of a patientfor placement within an aorta of the patient; and a flexible occludingmembrane having a lateral side coupled to the catheter shaft and adaptedto alternate between an expanded occluding configuration and a collapsedlesser occluding configuration in the aorta in response to blood flowfrom a left ventricle of the patient and in synchrony with ventriculardiastole and systole, wherein, when deployed in the aorta, the flexibleoccluding membrane is configured to inhibit blood flow from the leftventricle in the expanded configuration and to lessen inhibition of saidblood flow when in the collapsed configuration, and wherein the flexibleoccluding membrane has an opening to allow blood perfusion therethroughwhen in the expanded occluding configuration.
 2. The temporary aorticvalve apparatus of claim 1, wherein the flexible occluding membrane isadapted to assume the expanded occluding configuration in response toblood flow in the aorta during ventricular diastole.
 3. The temporaryaortic valve apparatus of claim 1, wherein the flexible occludingmembrane is adapted to assume the collapsed lesser occludingconfiguration in the aorta in response to blood flow therein duringventricular systole.
 4. The temporary aortic valve apparatus of claim 1,wherein the opening is positioned at substantially a center of theflexible blood occluding membrane.
 5. The temporary aortic valveapparatus of claim 4, wherein the opening and the center of the flexibleoccluding membrane are disposed at a distal tip of the flexible bloodoccluding membrane.
 6. The temporary aortic valve apparatus of claim 1,wherein the opening is positioned at a location offset from a center ofthe flexible occluding membrane.
 7. The temporary aortic valve apparatusof claim 1, wherein the flexible occluding membrane has a plurality ofopenings to allow blood perfusion therethrough when in the expandedoccluding configuration.
 8. The temporary aortic valve apparatus ofclaim 1, wherein the opening has a cross-sectional size of 50% or less,45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% orless, 15% or less, 10% or less, or 5% or less of the aorta.
 9. Thetemporary aortic valve apparatus of claim 1, wherein the catheter shaftcomprises a distal anchoring loop having an expanded, curvedconfiguration for anchoring the catheter shaft and the flexibleoccluding membrane in the aorta and a collapsed, straightenedconfiguration for advancement into or retraction from the aorta.
 10. Thetemporary aortic valve apparatus of claim 1, wherein the flexibleoccluding membrane has a conical shape.
 11. The temporary aortic valveapparatus of claim 10, wherein the conically-shaped flexible occludingmembrane comprises an annular proximal lip adapted to appose an innerwall of the aorta when the flexible occluding membrane is in theexpanded occluding configuration.
 12. The temporary aortic valveapparatus of claim 1, wherein the flexible occluding membrane is adaptedto be positioned within an ascending aorta of the patient to provideocclusion therein.
 13. The temporary aortic valve apparatus of claim 12,wherein the flexible occluding membrane is adapted to be positionedwithin the ascending aorta just above the Sinus of Valsalva and coronaryostia.